Future vehicle systems can be configured to interchange data, e.g. by means of vehicle-to-X communication (also referred to as “Car2X”). In particular, unprotected communication systems can, however, be manipulated, wherein for example spurious messages can be emitted and consequently malfunctions can be caused. Therefore, the information security of the relevant systems is pertinent to the protection of road users.
Messages to be sent can be protected by also sending pseudonym certificates which are embedded in the relevant message. Certificates usually have a specific temporal term of validity which is defined by a start and an expiration date. A new certificate must be used following the expiration date. By providing certificates with differently defined temporal terms of validity in a vehicle, a period which is longer overall can be attained with valid certificates, with certificates with a short validity. For example, 20 certificates with consecutive validity periods having a length of one week can be provided. To this end, it is assumed that the certificates can be updated during the maintenance interval of the vehicles, i.e. after approximately 2 years. This means that the vehicles would also have to carry certificates with a validity of up to 2 years in advance in a memory which is provided for this purpose. A revocation of the certificates is not envisaged.
The disadvantage of this prior art is that, in the event of a third party successfully accessing the code and certificate memory, bogus messages with a certificate which will actually only be valid in the future can be emitted. As a countermeasure, a very secure code and certificate memory could be provided, but the disadvantage of this is the comparative high cost.